Inkjet printers utilize printheads that include an array of tiny orifices through which ink is ejected on to paper or another print substrate. For some types of inks, it is desirable to treat the print substrate with a chemical agent that helps the ink adhere properly to the substrate or otherwise improves the condition of the substrate before or after ink is applied. Such treatment agents may be applied to the print substrate during printing operations through a printhead (or group of printheads) positioned near the ink printheads.
The same part numbers designate the same or similar parts throughout the figures.